Azimuthal Asymmetric Distribution of Hadrons Inside a Jet at Hadron Collider

We study the azimuthal asymmetric distribution of hadrons inside a high energy jet in the single transverse polarized proton proton scattering, coming from the Collins effect multiplied by the quark transversity distribution. We argue that the Collins function in this process is the same as that in the semi-inclusive deep inelastic scattering. The experimental study of this process will provide us important information on the quark transversity distribution and test the universality of the fragmentation functions.Comment: 10 pages, 4 figure

Possible evidence for the disk origin for the powering of jets in Sgr A* and nearby elliptical galaxies

The predicted radio flux for nearby ellipticals by the canonical ADAF(advection-dominated accretion flow) model is well above the observations. If the mass accretion rate favored by the numerical simulation were adopted, the ADAF model would also significantly overpredict the radio flux of Sgr A*. On the observational side, strong evidence for the existence of jets in Sgr A$^*$ and these ellipticals has been obtained. Based on these facts, we propose a truncated ADAF model for these sources. We assume that the accretion disk is truncated at a certain radius within which a jet forms by extracting the energy of the disk therefore the radio flux is greatly suppressed due to the radiative truncation of the disk and the fits to the observational data are excellent. For example, for Sgr A*, the model fits the spectrum very well from radio including the ``excess'' below the break frequency to hard X-ray under a high accretion rate near the simulation value; for M87, the predicted upper limit of the jet location is 24 $R_g$, in excellent agreement with the observational result of < 30 $R_g$. The success of the model supplies a possible piece of evidence for the disk rather than the hole origin for the powering of jets.Comment: 8 pages, 5 figures, uses mn.sty, accepted by MNRA

Luminous hot accretion disks

We find a new two-temperature hot branch of equilibrium solutions for stationary accretion disks around black holes. In units of Eddington accretion rate defined as $10L_{\rm Edd}/c^2$, the accretion rates to which these solutions correspond are within the range \dot{m}_1 \la \dot{m} \la 1, here $\dot{m}_1$ is the critical rate of advecti$. In these solutions, the energy loss rate of the ions by Coulomb energy transfer between the ions and electrons is larger than the viscously heating rate and it is the advective heating together with the viscous dissipation that balances the Coulomb cooling of ions. When$\dot{m}_1 \la \dot{m} \la \dot{m}_2$, where$\dot{m}_2 \sim 5 \dot{m}_1 < 1$, the accretion flow remains hot throughout the disk. When$\dot{m}_2 \la \dot{m}\la 1$, Coulomb interaction will cool the inner region of the disk within a certain radius ($r_{\rm tr} \sim$ several -- tens of Schwarzschild radii or larger depending on the accretion rate and the outer boundary condition) and the disk will collapse onto the equatorial plane and form an optically thick cold annulus. Compared to ADAF, these hot solutions are much more luminous because of the high accretion rate and efficiency, therefore, we name them luminous hot accretion disks.Comment: 12 pages, 6 figures, uses mn.sty, the final version accepted by MNRAS, discussion extended to emphasize the difference between ADAF and my mode

Influence of the additional second neighbor hopping on the spin response in the t-J model

The influence of the additional second neighbor hopping t' on the spin response of the t-J model in the underdoped and optimally doped regimes is studied within the fermion-spin theory. Although the additional second neighbor hopping t' is systematically accompanied with the reduction of the dynamical spin structure factor and susceptibility, the qualitative behavior of the dynamical spin structure factor and susceptibility of the t-t'-J model is the same as in the case of t-J model. The integrated dynamical spin structure factor spectrum is almost t' independent, and the integrated dynamical spin susceptibility still shows the particularly universal behavior as $I(\omega,T)\propto {\rm arctan}[a_{1}\omega/T+a_{3}(\omega/T)^{3}]$.Comment: 12 pages, Latex, Four figures are included, final published version [accepted for publication in Phys. Rev. B (July 1 issue)

Pseudogap effects on the c-axis charge dynamics in copper oxide materials

The c-axis charge dynamics of copper oxide materials in the underdoped and optimally doped regimes has been studied by considering the incoherent interlayer hopping. It is shown that the c-axis charge dynamics for the chain copper oxide materials is mainly governed by the scattering from the in-plane fluctuation, and the c-axis charge dynamics for the no-chain copper oxide materials is dominated by the scattering from the in-plane fluctuation incorporating with the interlayer disorder, which would be suppressed when the holon pseudogap opens at low temperatures and lower doping levels, leading to the crossovers to the semiconducting-like range in the c-axis resistivity and the temperature linear to the nonlinear range in the in-plane resistivity.Comment: 21 pages, Revtex, Six figures are include

Transverse Momentum Resummation for Dijet Correlation in Hadronic Collisions

We study the transverse momentum resummation for dijet correlation in hadron collisions based on the Collins-Soper-Sterman formalism. The complete one-loop calculations are carried out in the collinear factorization framework for the differential cross sections at low imbalance transverse momentum between the two jets. Important cross checks are performed to demonstrate that the soft divergences cancelled out between different diagrams, and in particular, those associated with final state jets. The leading and sub-leading logarithms are identified. All order resummation is derived following the transverse momentum dependent factorization at this order. Its phenomenological applications are also presented.Comment: 51 pages, 10 figure